Magnetic elements such as inductors are widely used in many electronic devices. Recently, the electronic devices are developed toward minimization. For reducing the overall volume of the electronic devices, the inductors and the conductive winding assemblies of the inductors are gradually reduced.
FIG. 1 is a schematic perspective view illustrating a conventional inductor. As shown in FIG. 1, the inductor 1 comprises a winding assembly 11 and a base 12. The winding assembly 11 is disposed on an upper surface 120 of the base 12. The winding assembly 11 comprises a magnetic core 110 and a winding coil 111. The magnetic core 110 is ring-shaped. The winding coil 111 is wound around the ring-shaped magnetic core 110. Several pins 121 are mounted on the base 12. The pins 121 have bending structures. Both terminals of the winding coil 111 are respectively wound around and connected to two different pins 121. The contact portions 121a of the pins 121 are connected to a circuit board (not shown), so that the winding coil 111 is electrically connected with the circuit board through the pins 121.
In the conventional inductor 1, the winding coil 111 is directly wound around the pins 121. In a case that the diameter of the winding coil 111 is relatively large, the pins 121 are readily suffered from deformation during the winding process. Under this circumstance, the performance of the inductor 1 is deteriorated. Moreover, the inductor 1 could be directly arranged on a circuit board according to a surface mount technology (SMT), and thus the inductor 1 could be also referred as a surface mount magnetic device (SMD). After the inductor 1 is placed on the circuit board by a placement machine, the inductor 1 and the circuit board are heated in a reflow furnace and thus the pins 121 of the inductor 1 are welded on the circuit board. If the pins 121 are suffered from deformation, a poor contact problem of the inductor 1 occurs.
Since the winding coil 111 is directly wound around the pins 121, the height h1 of the winding assembly 11 is also determined by the diameter of the winding coil 111. If the diameter of the winding coil 111 is relatively large, the height h1 of the winding assembly 11 is increased and thus the evenness of the winding assembly 11 is insufficient. In addition, since the winding assembly 11 is disposed on the upper surface 120 of the base 12, the total height of the inductor 1 is equal to the sum of the height h1 of the winding assembly 11 and the height h2 of the base 12. In other words, it is difficult to precisely control the overall height of the inductor 1. In addition, the layout space of the inductor 1 is very large.
For increasing throughput and yield, the inductor 1 should be mounted on the circuit board by an automatic placement process according to the surface mount technology (SMT). Since the evenness of the winding assembly 11 is insufficient, the upper surface of the winding coil 111 is not suitable as a sucking surface to be picked up by the automatic placement machine. In other words, the inductor 1 is manually mounted on the circuit board and thus the fabricating cost is increased.
There is a need of providing an improved inductor so as to obviate the drawbacks encountered from the prior art.